1. Field of the Invention
This invention relates to a data imprinting device for a camera and more particularly to a data imprinting device for a camera which is arranged to permit switch-over of the size of the photographing picture or image plane thereof between a standard or full size measuring 36 mm.times.24 mm and a half size measuring 18 mm.times.24 mm.
2. Description of the Related Art
Cameras of the kind arranged to permit photographing in the half image plane size have not been popular, with the exception of a time during which they enjoyed a boom, because of the considerably inferior quality of pictures obtainable with them. The majority of people have preferred to buy cameras of the 35 mm full-size photographing type. However, a recent improvement in the capacity of film has come to enable the half-size camera to give a finished picture which is not inferior to a picture obtained by the full-size camera as long as the picture is printed in the so-called service print size. This change, in addition to the economical advantage of having double the number of photographable frames, has come to bring the half-size camera before the footlights. However, the disadvantage of having the inferior picture quality evidently still shows when a commemorative photograph or the like is enlarged to a greater size.
In view of this, a camera which permits selection between the full size and the half size has been proposed in Japanese Laid-Open Patent Application No. SHO 54-26725, etc.
Meanwhile, cameras of the kind arranged to permit imprinting on the film some data such as a date have become popular. It has been desired to have these two functions incorporated in one and the same camera. However, an attempt to impart these two functions to one and the same camera encounters the following problems:
One problem resides in the size of data letters to be imprinted on the film. More specifically, the half size which is 18 mm.times.24 mm is one half of the full size which is 36 mm.times.24 mm. If an imprinting device is used both for imprinting data in the full size image plane and for imprinting in the half size image plane, the size of the imprinted letters is the same in both cases. Therefore, the ratio of the area of the imprinted data letters to the half-size frame area of the film is naturally twice as large as that of imprinted data letters to the full-size frame area. Assuming that the photograph is printed in the service size, for example, the imprinted letters in a half-size picture, which is as indicated by two-dot chain lines in FIG. 1 and also as indicated by FIG. 2 of the accompanying drawings, are so large and conspicuous because the size of letters becomes 1.5 times larger in both width and height than that of letters in a full-size picture that it ruins a precious commemorative photo or the like while the data letters imprinted in a full-size photo are of an adequate size.
A further problem resides in the positional location of the imprinted data letters on the half-size film.
There have been proposed methods of varied kinds for imprinting data on full-size film by driving a group of light emitting elements during film winding or rewinding. However, these methods bring about the following problem when they are applied to cameras of the full-half selection type:
FIG. 23 of the accompanying drawings shows a first example where the group of light emitting elements is arranged outside of an aperture of a camera according to one of the above stated methods. Referring to FIG. 23, on the right-hand side of the drawing is located a spool in one case and a film cartridge in another case.
1) In case where the group of light emitting elements is arranged on the side of the spool to imprint data during film winding: A film winding action causes the film 101 to move in the direction of arrow. In the full-size photographic mode, an exposed image plane 102a is shifted to a position 102b when one frame portion of film is wound up. In the process of this movement, the light emitting element group 103 is driven at a predetermined timing to imprint data in a position A on the image plane 102a. In the figure, a reference numeral 104 denotes an aperture provided for the full-size photographic mode.
In the half-size photographic mode, an exposed image plane 105a is shifted to be located in a position 105b upon completion of one frame winding. However, at this point of time, the image plane 105 on which data is to be imprinted has not yet completely passed the light emitting element group 103. It is, therefore, impossible to imprint data by driving the light emitting element group 103 during the one-frame winding. In this instance, therefore, data can be imprinted in a position B on the image plane 105a by driving the light emitting element group 103 during a next one-frame winding process. In the event of the half-size photographic mode, therefore, the length of time between the start of a winding action on the image plane 105a located in the position 105b and the start of light emission by the light emitting element group 103 differs from the length of time required for the full-size photographic mode.
2) In cases where data is to be imprinted during film rewinding with the light emitting element group 103 arranged on the side of the film cartridge: The film 101 moves in the direction of arrow when a film rewinding action begins. In the full-size photographic mode, the exposed image plane 102a moves to be located in the position 102b after completion of rewinding of one frame. During this movement, the light emitting element group 103 is driven at a predetermined timing to imprint data in the position A on the image plane 102a.
In the half-size photographic mode, the exposed image plane 105a moves to be located in the position 105b after completion of rewinding of one frame. At this stage, however, the data cannot be imprinted by driving the light emitting element group 103 during the process of one-frame rewinding, because the image plane 105a has not yet completely passed the light emitting element group 103. In this mode, therefore, data is imprinted in the position B on the image plane 105a by driving the light emitting element group 103 during the process of rewinding a next frame portion of the film. Like in the above stated case 1), the length of time between the start of a winding action on the image plane 105a and the start of light emission by the light emitting element group 103 differs from the length of time required for the full-size photographic mode.
FIG. 24 shows a second example of application, wherein the light emitting element group 103 is disposed within the aperture. Like in the first example, two cases are also conceivable. In one case, the spool is disposed on the right-hand side. In the other case, the film cartridge is disposed on the right-hand side. Since data imprinting during film rewinding is performed in the same manner as in the case of the first example, data imprinting during film winding is alone described below:
In the full-size photographic mode: The light emitting element group 103 is driven to imprint data in a position A on an exposed image plane 102a at a predetermined timing during the process of winding of the film 101. In the half-size photographic mode, the light emitting element group 103 is driven to imprint data in a position B on the exposed image plane 105a at a predetermined timing during the process of winding of the film 101. In this case, the moving extent of film from the start of film winding until arrival of a foremost imprinting point (front end of the position A or B) of the frame at the front of the light emitting element group 103 is m1 or m2 and thus varies with the photographic mode. The light emitting timing for imprinting data on each frame in the full-size photographic mode thus differs from the timing in the half-size photographic mode.
As apparent from the foregoing description of the first and second examples of application, the light emitting timing for data imprinting must be changed according to selection between the full- and half-size photographic modes when any of the different data imprinting methods is applied to the camera of the full-half selection type. Without any change in the light emitting timing, it would be impossible to have data imprinted always in an appropriate part of the image plane. Whereas, no solution of this problem has been proposed.